ABSTRACT
Size-selected submicron spheres become very useful building blocks if the spheres could be synthesized and integrated at any desired position. In particular, spheres having a similar size to visible-light wavelength have attracted much attention. Here, we show the synthesis and assembly of size-selected submicron gold spheres using pulsed laser ablation of a gold plate in a supercritical fluid. Four findings were obtained in the study. Submicron spheres with a narrow size distribution were generated, and the polydispersity was ≈ 6%. The average diameter was controlled from 600 to 1000 nm. A thermodynamic condition for scalable synthesis was found. The assembly of spheres onto a metal, carbon, or plastic substrate was accomplished.
ABSTRACT
Fluorescence-intensity enhancement of dye molecules was investigated using silicon submicron particles as a function of the particle size. Silicon particles with a size of 500 nm gave an enhancement factor up to 180. Measurement of scattering spectra revealed that the localized electric field at the particle enhances the fluorescence intensity.